Kenneth Lonergan’s long-awaited follow up to the under-seen Margaret (2011) is a kind of companion piece to its predecessor. If both films are epics, tragedies, operas of suffering – in Manchester By the Sea the angst is emotional rather than intellectual. Where the former explored manic, neurotic female energy, externalised and emoted at fever pitch, this is its inverse; the black bile of grief turned inward and frozen, clogging the chest cavity of its male vessel.

From the sibling duo in his first feature You Can Count On Me (2000) to the fraught mother-daughter relationship at Margaret’s core, Lonergan remains fascinated by the inner workings of family relationships. Here his focus is fathers and sons – be they biological or surrogate, heroic pairings or makeshift partners. Lee Chandler (Casey Affleck) is an isolated, introverted janitor living in joyless solitude. He shovels the snow blocking the entrance to his barely furnished one-bedroom apartment, sparing no passing pleasantries as he fixes household leaks in the frigid Boston winter. When Lee’s older brother Joe (Kyle Chandler) dies, the care of his teenage son Patrick (Lucas Hedges) falls to him, so he returns to the fishing town where he grew up.

Manchester by the Sea is as flat and grey as Boston – the palette of grief is unchangingly colourless. Yet no matter how it looks from the outside, Lonergan takes care to show the many shades of emotion that bereavement encompasses. Despite the bleak subject material, there are bright flickers of fury and tenderness and humour. There is a bluntness, and a brittleness, to the comedy. Much of this is found in the relationship between Lee and Patrick; when the pair argue about the matter of Joe’s remains, it is agreed – reluctantly – that his body should live in the funeral home’s freezer (like a ham) until the ground softens in the spring.

Lee with his nephew Patrick (Lucas Hedges)

Patrick is on the school hockey team, in an after-school rock band and trying to get into the pants of two different girls; he’s rowdy, randy and determined to continue playing the role of the popular kid. Lee struggles to balance his laissez-faire attitude to other people with his newfound responsibility to his adolescent nephew. Similarly, Patrick’s rambunctious (if not exactly rebellious) energy rubs up against his need for a father figure. The pair bicker over Patrick’s girlfriends; about what will happen to Joe’s boat; about Patrick’s desire to rekindle his relationship with his absent alcoholic mother Elise (Gretchen Mol).

However, though Joe’s death forces him to recalibrate his life to accommodate Patrick, Lee can’t simply snap into the rhythm of family life. Affleck’s Lee is cold and closed-off, unexplained contrition clouding his steely gaze. Lonergan and Affleck withhold the story behind his deep sense of shame for the film’s first hour, and so when his tragic, traumatic past is finally revealed so too is the utter effort taken to supress it. Affleck’s performance gives ragged flesh to Lee’s deep psychic wounds.

Michelle Williams as Randi

There is one scene that sees Lee briefly reunited with his ex-wife Randi (Michelle Williams) when the two cross paths on the street. An inarticulate exchange is quietly devastating – and a testament to Lonergan’s gift with actors. (His background is writing for the stage.) The way Affleck, Hedges and Williams inhabit his characters in all of their complicated, uncomfortable sadness is the film’s strength, making the time spent with them an exercise in human grace – and as pleasurable a viewing experience as a film about death could hope to be.

In Manchester by the Sea, the waves of grief are choppy and unpredictable, cresting and receding with force and without warning, as those who have lived through the death of a loved one will know. The film’s editing and cacophonous score are similarly unsmooth – but a sleeker film would be a more timid one, too. Best of all, the film resists the tidy resolution of closure, aiming for something more intimately truthful to the lived reality of trauma.